MS Windows workflow: an explanation

I have been pretty much interested in Microsoft Windows Workflow lately and trying to figure out how to explain to my 13 year old nephew its concepts and simple applications. I run into this article, informative and quite useful but not really simple at all (maybe because of my bad English)

I simply think workflow can be defined as a series of rule based steps designed to accomplish a specific task. It can be used to create a simplified model of a complex system which is to demonstrate how the complex system functions in the real world. The three main issues presented in the article confuse me; I realize my understanding about WF only matches the first and I don't understand what they explain in the second and third issues at all.
Could someone offer me a short explanation over the article's main ideas as well as show me how WF can be of real help in practical applications you might have done or know of ? Thank you a lot.

Different projects require similar tools and functions - so Microsoft provided a unified solution set when it created WorkFlow.

The alternative is to invent your own solutions using the tools that were previously available.

You can determine if WorkFlow will be useful for you by developing a set of functional requirements for your application, then matching them up with the various choices. One of the choices will be WorkFlow.

Other considerations are: is WorkFlow an efficient implementation of these functions? Is it a stabel product? Will it continue to be offered in the future? This is a risk-evaluation.

Different projects require similar tools and functions - so Microsoft provided a unified solution set when it created WorkFlow.

The alternative is to invent your own solutions using the tools that were previously available.

You can determine if WorkFlow will be useful for you by developing a set of functional requirements for your application, then matching them up with the various choices. One of the choices will be WorkFlow.

Other considerations are: is WorkFlow an efficient implementation of these functions? Is it a stabel product? Will it continue to be offered in the future? This is a risk-evaluation.